I’m looking for methodological information with respect to perturbed auditory feedback paradigms. The idea is we want to record people’s speech output, manipulate it (e.g. shift formant frequency) and play it back to the speaker through headphones, and this all in realtime (i.e. no noticeable delay between speech onset and feedback onset).

There is a bunch of literature using this paradigm, but I am looking for some methodological information about how to implement such algorithms. I.e. are there any relatively straightforward software solutions out there? What kind of implementation do people use for these paradigms, and what kind of delays are there between speech onset and feedback onset?